Feed mechanism for stapling machines



'Oct. 21, 1947. c. M. LINDSTROM FEED MECHANISM FOR STAPLING MACHINESFiled June 28, 1944 3 Sheets-Sheet l 3 Sheets-Sheet 2 Oct. 21, 1947. c.M. LINDSTROM FEED MECHANISM FOR STAPLiNG MACHINES Filed June 28, 1944FEE y NH HHI HHHHHHHHHH UM u H u E c E c c E E I x I Oct. 21, 1947.

C. M. LINDSTROM FEED MECHANISM FOR STAPLING MACHINES 3 Sheets-Sheet 15Filed June 28, 1944 Q IIAAAMMM: I

Patented Oct. 21, 1947 FEED MECHANISM FOR STAPLING MACHINES Charles M.Lindstrom, East Greenwich, R. 1., assignor to Boston Wire StitcherCompany, Warwick, R. I., a corporation of Maine Application June 28,1944, Serial No. 542,529

13 Claims.

supply of V fastener-applying means, and means slidable on the arm forretracting the pusher to permit loading of the fasteners on the arm.

Another object is to provide an implement of the type indicated having adivided or two-part housing for enclosing the fastener-applying meanswith one member of the housing constituting a manually-slidable elementmovable along the magazine-arm and engageable with the pusher towithdraw the latter to inoperative position.

Another object is to provide an implement of the type indicated in whichthe slidable member mounts a coil-spring for automatically operating thepusher to feed the fasteners along the magazine-arm and adapted to bewound under tension when the slidable member is slid rearwardly duringretraction of the pusher to inoperative position,

Another object is to provide an implement of the type indicated in whichthe pusher-spring normally overlies the top of the fasteners supportedon the magazine-arm to prevent their displacement during operation ofthe implement.

Another object is to provide an implement of the type indicated havingmanually-releasable means for latching the slidable member in operativeposition.

Another object is to provide an implement of the type indicated in whichno latching means is required for retaining the pusher in retractedposition during the loading of the fasteners on the magazine-arm.

Another object is to provide an implement of the type indicated having adetent connected to the slidable member and engageable with latchingmeans at the forward end of the magazine arm for maintaining theslidable member in forward operative position and the pusher-springtensioned in position overlying the fasteners on the magazine-arm toprevent their displacement.

Further objects of the improvement are set forth in the followingspecification which describes two forms of construction of theinvention, by way of example, as illustrated by the accompanyingdrawings. In the drawings:

Fig. 1 is a side elevational view of an implement incorporating thenovel features of the present invention and showing the pusher asoperative to advance-thefasteners along the magazine-arm to feed them tothe fastener-applying means;

Fig. 2 is a plan view of the same;

Fig. 3 is a transverse sectional view on line 3-3 of Fig. 1 showing the'means for mounting the coil-spring for the pusher within the slidablemember;

- Fig. 4 is a transverse sectional view of the magazine-arm taken online 4-4 of Fig. 1;

Fig. 5 is a side elevational viewof. the magazine-arm showing theslidable member as released and slid rearwardly to retract the pusher toinoperative position whereof to permit loading of the fasteners onto thearm;

Fig. 6 is a side elevational view of a magazinearm shown in reducedscale and illustrating a modified form of the means for retaining theslidable member in its operative position and also indicating the mannerin which the detent-element overlies the fasteners on the arm to preventtheir displacement;

- Fig. 7 is a view similar to Fig. 6 showing th detent-means as releasedand the slidable element and pusher retracted to inoperative position topermit loading of the fasteners on the mag-azine-arm;

Fig. 8 is an elevational view of the rearward end of the magazine-armshown in Fig. 6; and

Fig. 9 is a plan view of the slidable member and associated parts shownpart-sectional on line 9-9 of Fig. 6.

Various types of stapling implements and similar devices comprise amagazine-arm for containing a supply of staples with staple-applyingmeans carried at one end thereof and a springactuated staple-pusher forautomatically feeding the staples thereto. In certain devices of thischaracter, the staple-supporting core is enclosed within a tubularmagazine or sheath and the staples loaded thereinto by insertin themeither through the rearward or forward end of the ma azine and slidingthem onto the core. Where the staples are loaded through the front endof the device they must be forced rearwardly onto the core against theaction of the spring-actuated pusher and in other forms of constructionwhere they are inserted through the rearward end of the magazine thepusher must first be either raised above the core or bodily removedtherefrom to enable the staples to be slid into place. Still anothertype of stapling device employs a magazine comprising a so-calledtop-loading core onto which the staples are loaded vertically and ahollow cover member partly enclosing the core and arranged for slidingor pivotal movement to uncover the core for the reception of thestaples. When devices of the last-noted type are employed it iscustomary to first open the magazine and thereafter manually displacethe pusher against the action of its propelling spring so that a freshsupply of staples may be placed on the core; after which the pusher isreleased to engage the staples and feed them along the core to thestaple-applying means. When the pusher is retracted rearwardly manually,latching means are usually provided for retaining it in inoperativeposition against the action of its spring and it sometimes happens thatthe latching means becomes accidently released to cause the pusher to bepropelled forwardly at a rapid rate to disarrange the staples.

The present invention relates more particularly to stapling devices ofthe top-loading type and comprises, in general, a magazine-arm or coreupon which the staples are supported to adapt them to be fed forwardlyto the stapleapplying means at the forward end of the arm by means of a.staple-pusher. The staple-pusher comprises means engageable with thestaple-core to prevent it from rising thereon and is adapted to bepropelled forwardly by means of a coilspring mounted in a memberlikewise arranged for sliding movement on the core. The slidable memberforms a complementary part of a housing for enclosing thestaple-applying mechanism and normally it is held in forward position bya manually-releasable latch, When the latch is released and the slidablemember is withdrawn rearwardly it will engage with means on the pusherto retract the latter so as to permit a supply of staples to be loadedonto the core. As the slidable member is slid rearwardly the coil-springwill be wound under tension, so that due to its inherent resiliency, asthe member engages the pusher the tension of the spring will maintainthese parts in engagement as a unit which may be retractedlongitudinally of the staple-core. By this form of construction andcooperative relation of the parts it is unnecessary to providedetent-means for retaining the pusher in retracted position. The lengthof spring extending between the slidable member and pusher normallyoverlies the staples mounted on the core to prevent them from beingdisplaced therefrom.

In another embodiment of the invention, staple-retaining means areprovided in the form of a latch-bar, which may be pivotally mounted onthe slidable member and adapted to engage means at the rearward end ofthe staple-core to maintain the member in operative position. Thelatch-bar is arranged to overlie the core and is especially adapted foruse in hammer-tackers or other implements subject to severe impacts andrough usage liable to cause the staples to be jarred out of place. V

Referring first to Figspl to of the drawings, a conventional type ofstapling machine is illustrated therein as comprising a base 2 providedwith a clinching anvil 3 at its forward end and having upstanding earsor flanges 4 "at its rearward end. Pivoted between the spaced ears 4 bya transverse pin 5 is a stapling-arm, indicated generally by thereference character 9. The arm 9 comprises a magazine-core H] forsupporting a series of staples S with a housing 8 at its forward end forenclosing the staple-driving mechanism, to be described hereinafter. Thestaplingarm 9 normally is held in raised position by means of aspring-actuated plunger 1 slidable in the base 2 and engaging the underside of the arm.

Referring particularly to Figs. 3 and 4, the staple-core I!) may be inthe form of a bar of substantially rectangular cross-section having arelatively wide lower portion ll bored transversely to receive the pivotpin 5 and a narrower upper portion [2 for supporting the staples S instraddled relation thereon. Between the lower and upper portions II and[2 of the bar the sides of the core ID are provided withlongitudinallyextending grooves or guideways l4 and spaced above theguideways [4 are similar guideways E5; the two guideways l4 and i5 beingemployed for a purpose to be explained later.

The forward end of the core Ii] is narrowed in width to provide oppositerecesses is for receiving upstanding flanges or side-plates l8 suitablyfastened to the core to constitute part of the head or housing 8.Vertical grooves ii) on the inner face of each plate l8 provide aguideway or throat 20 through which the staples S are driven into thework. Mounted for reciprocation in the guideway 29 is a staple-driver 22operatively connected to a plunger .23. The plunger 23 is ofsubstantially U-shape in crosssection, see Fig. 2, and provided withinturned runners 24 adapted to slide in vertical slots 25 in the outerfaces of the side plates IS. The plunger 23 normally is held in raisedposition with the lower end of the driver 2-2 spaced slightly above theforward end of the core 10 by means of a helical spring 28 having itslower end seated upon a ledge 29 within the housing 5 and its upper endabutting a knob 30 fastened to the upper end of the plunger. The upwardmovement of the plunger 23 and driver 22 is limited by the engagement ofa latching member 3| carried by the plunger with a shoulder 32 on thehousing 5. A staple-supporter 33 of usual construction and actuated by aspring-pressed plunger 34 slidable in a bore in the forward end of thecore I8 is adapted to engage the cross-bars of the staples S to supportthe latter as they are driven through the throat 20 and into the work.

The staples S are arranged with their crossbars resting upon the top ofthe core to and their legs straddling the sides thereof as shown in Fig.3. The staples S are fed forwardly along the core it) to position theforemost staple in the throat 2i] beneath the driver 22 by means of apusher 35. As shown in Figs. 1 and 4, the pusher '35 consists in aninverted U-shape'd element arranged with its upper portion 36 restingupon the top of the core I9 and its sides 37 straddling the sidesthereof. The rearward end of the pusher 35 has portions of its sides 31bent inwardly to provide runners 39 which engage in the-longitudinalguideways 15 in the sides of the core It? to adapt the pusher to slidealong the core while preventing it from upward displacement. Therearward end of the top 36 of the pusher 35 is provided with ears fie,see Figs. 2 and 4, which extend laterally beyond the sides of the coreill for a purpose hereinafter explained.

The staple-pusher 35 is adapted to be slid forwardly along the core If]by means of a ribbonlike spring 64 having one end fastened to itsrearward end by a rivet 45, see Figs. 1, 2 and 4.

As shown in Fig. 3, the spring 44 may be formed of slightly arcuateshape in cross-section to increase its strength and rigidity. Theforward end of the spring 4 3 is coiled around a stud ll extendingbetween the sides of a bonnet-like member 50. The member 50 isconstructed from sheet-metal to provide a sloping top wall 5!, see Fig.1, with side walls 52 folded downwardly therefrom. The lower ends of theside walls 52 are bent inwardly to provide runners 53 adapted to slidein the guideways M in the staple-core iii. The side walls 52 are furtherprovided with horizontal slots 55 in their rearward edges for a purposehereinafter explained. To provide a rigid structure the side walls 52may be connected by a transverse screw 51 passing through aspacer-sleeve 58 interposed between the side walls. The stud 41,previously mentioned as constituting a support for the coils of thepusherspring 44, also forms a cross-strut between the walls 52 of theslidable element 56.

As shown in detail in Fig. 3, the stud 41 has a slotted head 6| abuttingthe outer surface of one of the side walls 52, a reduced central portion62 and a further reduced shank 63 projecting through a hole in theopposite side wall. The reduced portions 92 and 63 of the stud 41 areformed with a. diametrical slot 65 extending longitudinally thereof, seeFig. 3, for holding the bent end of the inner coil of the spring 44which is inserted thereinto with its terminal portion 66 swaged overagainst the periphery of the stud as shown by dotted lines in Fig. 1.The coil-spring 44 is held axially in place abutting a shoulder 61 onthe stud 41 by means of a washer 68 on the reduced shank 63, see Fig. 3.The outer projecting end of the shank 63 is screw-threaded to receive anut 69 set up against the side wall of the member 50. The stud 41 isheld from turning in the member 50 by means of a key 70 constituted by arelatively small pin inserted through its head and engageable in a slotor keyway H in the side wall 52 of the member. To assemble the stud 4'1and spring 44 in place in the slidable member 50 the stud is insertedthrough the alined holes in the element and during this insertion theinner hooked end of the spring placed in the slot 65 of the stud, thewasher 68 being applied simultaneously to the shank 63. With the hookedend of the spring 44 held in the slot 65 of the stud 41 and its oppositeend attached to the staple-pusher 35 the stud may be turned in clockwisedirection, as viewed in Fig. 1, to wind orcoil the spring about the studin a manner similar to that of winding a clock spring. After the springhas been wound into a volute coil of sufiicient tension to properlyactuate the pusher 35 the key 10 is alined with and engaged in the slotor keyway ll in the member 50. With the spring 44 thus held undertension the nut 69 is screwed onto the shank 68 of the stud 4'! and setup against the side of the member 50 to secure the parts in adjustedrelationship.

The slidable member 50 normally is maintained in forward position on thecore H! where it serves as a closure for the rearward end of the housing8 containing the staple-driving mechanism as illustrated in Fig. 1. Themember 56 is held releasably in this position by means of a spring-latchcarried by the member and formed with a detentear 86 engageable inalined notches 16 in the upper edge of the side plates 18 of the housingor head 8. At the rearward side of the notches 16 the side plates I8 areformed with beveled or inclined edges 86 adapted to raise the end of thelatch 15 to cause its detent-ear 80 to snap into the notches. The latch15 consists in a leafspring attached to the sloping top 51 of the memberby a rivet 18 and provided at its forward end with a downwardly bent earconstituting the detent 80 engageable with the rearward edges of thenotches 16. As shown in Figs. 1 and 5, the rearward edges of the notchesl6 slope forwardly toward the front end of the device'so that theengagement of the detent-ear 80 of the latch I5 therewith tends to drawthe slidable member 50 forwardly to maintain it in closely abuttingrelation to the side-plates l8 of the housing 8. At its forward end thelatch I5 may be extended laterally to provide finger-holds 82, see Fig.2, for facilitating the unlatching of the parts. When the latching meansis disengaged the member 50 may be slid rearwardly to retract the pusher35 in the manner as explained later, and to prevent complete withdrawalof the pusher from the core In an abutment 83 is provided. As shown inFigs. 1 and 2, the abutment 83 may be constituted by a screw threadedinto a tapped hole in the rearward end of the core I0 and provided witha head, the periphery of which extends above the top of the core to forma stop for engaging the rearward end of the pusher to limit its rearwardmovement, see also Fig. 5. The complete stapling implement having beendescribed in detail. its method of operation is as next explained.

Assuming that the parts of the stapling machine are in the relationshipshown in Fig. 1 of the drawings that is, with the slidable member 5!]latched in its forward position and a supply of staples S supported onthe core I0, the machine is ready for a staplin operation. With thelower end of the staple-driver 22 held above the forward end of the corein the staple-pusher 35 will have advanced the strip of staplesforwardly along the core under the action of the spring 44 to positionthe foremost staple of the series in the throat 20. To apply a staple Stothe work W, the latter is first placed upon the clincheranvi1 3 andthe stapling arm 9 swung downwardly against the action of thespringoperated plunger 1 to cause its head to bear against the work inthe manner indicated by dash-lines in Fig. 1. Pressure applied to theknob 30 will cause the plunger 23 to descend on the head 8, therebyactuating the driver 22 to shear the foremost staple S from theremaining staples in the strip and force it downwardly through thethroat 20 to drive its legs through the work and clinch them against theunderside thereof by means of the clincher 3.

When pressure on the knob 30 is released the stapling arm 9 will swingupwardly and the plunger 23 and driver 22 will ascend to the positionshown in Fig. 1. Then, as the lower end of the driver 22 is raised abovethe core 10 the staple-pusher 35 will be advanced by the spring 4 tofeed the next succeeding staple S into the throat 20 in readiness to bedriven into the work when the staple-driving mechanism is againmanipulated. The operation of applying staples to the work may berepeated as long as a supply of staples remains in the magazine andduring the driving operations the remaining staples will be held down onthe core Ii) by the pusherspring 44 which, as shown in Fig. 1, overliesthe staples in closely adjacent relation thereto; it being noted thatthe staples on the core within the head 8 are held in place by overlyingledges 26 as usually provided in machines of this type.

After the last staple S of the serieshas been positioned within thethroat 2!! 'thepusher 35 will have "moved forwardly sufdciently to causeits laterally proje'cting ears. 40 to enter the slots 55 inthe sidewalls 52 of the slidable member 50 and engage the inner ends of theslots whereby to prevent the forward end of the pusher from underlyingthe driver 22, thus guarding against its being struck by the driverduring unwarranted actuation thereof. The staples S are usuallyreplenished before the entire supply is exhausted and to enablethe'operator to determine the number of staples remaining on the core 8openings 85 may be provided in the side plates 18 of the head 8 throughwhich the staples are visible.

When it is desired to reload the core Ill with a iresh supply of staplesthe spring latch 15 is pried upwardly to disengage its detent-ear 80from the notches E in the upper edge of the sideplates 18 of the head 8.With the slidable member 50 thus released, it may be slid rearwardlyalong the core H) with its runners 53 riding in the guideways I4. Asexplained above, as the last staple S is fed beneath the staple-driver22 the ears 40 on the pusher 35 will enter the slots 55 of the elementEll and engage the ends thereof so that as the element is retracted inthis manner it will slide the pusher rearwardly. Regardless of theposition of the pusher 35 on the core l0, however, as the member 56 isretracted it will be moved across the staple-pusher to cause thelaterally-projecting ears 40 on the latter to enter the slots 55 andengage the inner ends thereof, see Fig. 5. During the movement of themember 55 toward the pusher 35 the spring 44 will wind around the stud4? so that the tension of the spring will maintain the cars 40 of thepusher 35 seated against the inner ends of the slots 55. Stated anotherway, the length of spring 5 extending between the member 50 and thepusher 35 will be maintained under tension to yieldingly connect theseparts for unitary sliding movement in either direction along the corel8.

When the slidable member 50 has been retracted to a position adjacentthe rearward end of the core It], as illustrated in Fig. 5, the end ofthe pusher 35 will engage the screw-head or abutment 83 to preventcomplete withdrawal of these parts from the core. The core thus will beuncovered throughout substantially its entire length to adapt a freshvstrip of staples S, represented at S in Fig. 5, to be placed thereon inthe manner indicated by dash lines in this latter view. After a freshsupply of staples has been placed on the core 10 the member 59 is slidforwardly and eventually the pusher 35 will engage the rearward end ofthe staple strip and move it forwardly until the foremost staple ispositioned within the throat 26. At this juncture the forward movementof the pusher 35 will be arrested and continued movement of the member50 will cause a length of the tensioned spring 44 to be drawn from thecoil surrounding the stud 47. As the member '58 approaches the limit ofits forward movement the detent-ear 80 on the latch 75 will ride up theinclined surfaces 86 on the side-plates #8, see Figs. 1 and 5, andfinally snap into the slot, 16 to maintain the element in abuttingengagement with the edges of the side-plates of the head 8 in the mannerpreviously explained. With the pusherspring 44 thus ten'sioned it willact to advance the .pusher35 following each stapling operation '15Hated.

8 whereby to feed the foremost staple of the series into the throat 20;

Figs. 6 to 9 of the drawings illustrate a modified form of constructionof the staple-feeding and pusher-retracting means. Since the mainelements of the device are of substantially the same construction asthose previously described in connection with the machine illustrated inFigs. 1 to 5, like reference characters are used to indicate like parts.

The modified form of device shown in Figs. 6 to 9 includes a difieren-tconstruction of the latching means for retaining the slidable member 50in its forward position. This latching means consists in a bar '90pivotally mounted within the slidable member 50 on a stud 9| andextending rearwardly therefrom to adapt it to overlie the pusher-spring44 whereby to further guard against displacement of the staples on theCore ill. The rearward end of the latch-bar is notched as indicated at92, see Fig. 8, to adapt it to straddle the sides of a spring-detent 93attached to the end of the core H by screws 94; The resilient detent 93tends to force the latch-bar 90 forwardly to maintain the member 50 inoperative position abutting the edges of the side-plates l8 of the head8. The forward end of the latch-bar 90 is bifurcated, see Fig. 9, toform bearing ears 96 for pivotally mounting it onthe stud 9!. As shownin Fig. 9, the bearing ears -96 straddle the sides of the coil spring 44to hold it in central position on the stud 9i. As in the constructionpreviously described, the stud 9! may be keyed to the member 50, afterthe spring 44 has been wound under tension, by means of a pin or key 10and the stud secured in place by a nut 69.

When it is desired to retract the pusher 35 to permit reloading of thecore H! with a stick of staples the rearward end of the latch-bar 90 ispried upwardly to disengage it from the spring detent 93, whereupon itmay be grasped in the fingers and withdrawn rearwardly to retract themember 50 and pusher 35 to the position shown in Fig. '7, the end of thepusher finally bringing up against the detent 93 to arrest movement ofthe parts in this direction. After a strip S of staples S has beenplaced on the core Hi the member 50 is slid forwardly and the latch-bar90 engaged with the resilient detent 93 to lock the elements inoperative relationship. It will be apparent from the above descriptionthat the latch-bar 90, in addition to serving as the means formaintaining the elements in cooperative relationship, also functions asa guard to prevent displacement of the staples on the core Ill. Thisfeature of improvement is especially desirable for use in staplingimplements of the hammertacker and other types which are subjected tosevere impacts and rough usage.

It will-be observed from the foregoing specification that the presentinvention provides a stapling implement in which the staples may beapplied vertically to the top of the staple-core for loading the deviceand further contemplates improved means for retracting thestaple-feeding mechanism to permit such loading. Due to the factthatth'epusher-spring is slidable with the staple-pusher to inoperative orretracted position, the usual detent-means for retainin the pusher inretractedposition against the action of a pusher-spring are not requiredand conseuently the danger of accidental release of the pusher and itsunwarranted actuation is elimi- As a particular feature of improvement,the present invention provides in combination with a top-loadingmagazine, means for automatically winding up the pusher-spring at apoint directly above the pusher when the latter is retracted whereby toexpose an extensive length of the staple-core for supporting a maximumnumber of staples. This results in improvement over similardevices ofprevious types in which the pusher-spring is compressed rearwardly ofthe pusher when the latter is withdrawn to inoperative position and thusoccupies space which might otherwise be employed for containing thestaples. Furthermore, in the present improved machine, the pusher-springserves an added purpose, that of overlying the top of the staples toprevent their displacement on the magazine-core and thereby eliminatingthe need for a separate cover, slide or other closure as usuallyprovided in top-loading staplers.

While two forms of construction of the invention are herein illustratedand described, it is to be understood that other modifications may bemade in the structure and arrangement of the parts of the device withoutdeparting from the spirit or scope of the invention. Therefore, withoutlimiting myself in this respect, I claim:

1. A fastener-applying implement comprising a top-loading magazine-armfor supporting a supply of fasteners, a housing at the forward end ofthe arm, means for feeding the fasteners along the arm, and meansmounted on the housing and retractible by sliding the housinglongitudinally of the arm, said retractible means normally extendingfrom the housing in overlyin relation to the fasteners on themagazine-arm for preventing upward displacement of the fasteners.

2. A fastener-applying implement comprising a top-loading magazine-armfor supporting a supply of fasteners, a housing at one end of the arm,and means for covering the top of the magazine-arm to prevent upwarddisplacement of the fasteners comprising a resiliently-retractibleelement extending longitudinally from the housing in overlying relationto the fasteners on the arm, said element being retractible into thehousing to uncover the magazine-arm for supplying fasteners thereto.

3. A fastener-applying implement comprising a top-loading magazine-armfor supporting a supply of fasteners, a member movable longitudinally ofthe arm, and means carried by said member and extending therefrom inoverlying relation to the fasteners on the magazine-arm, said meansbeing retractible on the member to uncover the magazine-arm forsupplying the fasteners thereto.

4. A fastener-applying implement comprising a top-loadin magazine-armfor supporting a supply of fasteners, a pusher for feeding the fastenersalon the arm, a member movable longitudinally of the arm, and resilientmeans extending from said member in overlying relation to the fastenerson the arm with its end connected to the pusher, said resilient meansbeing retractible on the slidable member when the latter is movedlongitudinally of the arm whereby to uncover the magazine-arm forreceiving a supply of fasteners.

5. A fastener-applying implement comprising a top-loading magazine-armfor supporting a supply of fasteners, a member movable along themagazine-arm, means for normally maintaining said member in positionadjacent one end of the arm, and means carried by the movable member andnormally extending therefrom in overlying relation to the fasteners onthe arm to prevent their displacement, said last-named means beingretractible on the slidable member as the latter is slid along the armwhereby to uncover the magazine-arm to permit application of thefasteners thereto.

6. A fastener-applying implement comprising a top-loading magazine-armfor supporting a supply of fasteners, a member slidable on the arm andnormally positioned adjacent its end, a pusher for feeding fastenersalong the arm, and retractible means extending between the slidablemember and the pusher for operating the latter, said slidable memberbeing engageable with the pusher during its sliding movement to withdrawthe pusher from operative position.

'7. A fastener-applying implement comprising a top-loading magazine-armfor supporting a supply of fasteners, a pusher slidable on the arm forfeeding'the fasteners therealong, means normally positioned adjacent oneend of the magazinearm and slidable longitudinally thereon, andresiliently-operated retractible means carried by the slidable means andconnected to advance the pusher, said slidable means being engageablewith the pusher, to retract the latter from operative position'duringmovement of the slidable means on the arm. V

8. A fastener-applying implement comprising a top-loading magazine-armfor supporting a supplyof fasteners, a pusher'slidable on the arm forfeeding the fasteners therealong, a member slidable on the arm,manually-releasable means for normally maintaining said member inposition adjacent one end of the arm, retractible means carried by theslidable member and connected to slide the pusher, and means on thepusher engageable by the slidable member as the latter is slid on thearm to withdraw the pusher from operative position whereby to permitloading of a supply of fasteners on the magazine-arm.

9. A fastener-applying implement comprising a top-loading magazine-armfor supporting a sup-, ply of fasteners, a pusher slidable on the armfor feeding the fasteners therealong, a member slidable longitudinallyof the arm, latching means for normally maintaining said member inposition adjacent one end of the arm, a spring coiled on the slidablemember and extending therefrom to overlie the fasteners on the arm withits terminal portion connected to the pusher, and means on the pusherengageable by the slidable member when the latter is slid on the armwhereby to withdraw the pusher from operative position.

10. A fastener-applying implement comprising a top-loading magazine-armfor supporting a supply of fasteners, a pusher slidable on the arm forfeeding the fasteners therealong, guideways extending longitudinally ofthe arm, a member provided with means engageable with the guideways toslidably mount it thereon, latching means for normally maintaining saidmember in position adjacent one end of the arm, and a volute springcoiled on the slidable member with its end connected to operate thepusher, said slidable member being adapted to engage the pusher andwithdraw it from operative position when said member is slid rearwardlyon the arm.

11. A fastener-applying implement comprising a top-loading magazine-armfor supporting a supply of fasteners, said arm provided with two sets oflongitudinally-extendin guideways on its sides, a slidable memberprovided with runners engageable with one set of guideways on the arm toadapt it to slide longitudinally thereof, latching means for retainingsaid slidable member in position adjacent one end of the arm, a pusherhaving runners engageable with the second set of guideways to adapt itto slide longitudinally of the magazine-arm, and retraotible meansconnected between the slidable member and the pusher for operating thelatter, said slidable member operating to withdraw the pusher fromoperative position when the member is slid rearwardly on the arm topermit a supply of fasteners to be applied to the magazine-arm.

12. A fastener-applying implement comprising a top-loading magazine-armfor supporting a supply of fasteners, detent-means at one end of thearm, a member slidable longitudinally of the magazine-arm, latchingmeans carried by the slidable member and engageable with the detentmeansfor maintaining said member in adjacent relation to the end of the arm,a pusher slidable on the magazine-arm, and a spring coiled on theslid'able member with its opposite 'end connected to the pusher foradvancing the latter along the magazine-arm to feed the fastenerstherealong, said member being engageable with the pusher to withdraw itfrom operative position'when said member is slid rearwardly on the arm.

13. A fastener-applying implement comprising a top-loading magazine-armfor supporting a supply of fasteners, a hollow member slidablelongitudinally of the arm, a pusher slidable on the arm for feeding thefasteners therealongresilient means held under tension on the slidablemembe! and connected to the pusher for operating the latter, means formaintaining the slidable member in adjacent relation to one end of thearm comprising a latch-bar pivoted to said member, a retractible memberextending longitudinally from the slidable member in overlying relationto the fasteners on the arm, and detentmeans on the arm engageable bythe latch-bar, said bar being releasable from the detent-means to permitthe slidable member to be slid on the arm and said member beingengageable with the pusher for withdrawing the latter from operativeposition to permit loading of the magazine-arm with a supply offasteners.

CHARLES M. LINDSTROM.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

